Why aren't the field measures I just made appearing on my assignment in the app?

When you create Field Measurements in Obzervr Manager, there is a key additional step so that they show on the Capture app. 

You will need to add the Field Measurement Section to the Assignment Type in Obzervr Manager. Then, you will need to sync your device and create a new Assignment. Your Field Measurements should show in the Assignment. 

Use Series? 

You will need to add the Field Measurements to the Series Type and ensure that the Series Type is attached to the Assignment Type. Sync your device and create a new Assignment - your Field Measures will be in the new Assignment :)